Electric riveting-machine.



J BURKE.

ELECTRIC RIVETING MACHINE.

APPLICATION FILED JUNE 13, 1907.

1,062,883. Patented May 27, 1913.

3 SHEETS-SHEET 1.

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ELECTRIC RIVETING MACHINE.

APPLICATION FILED JUNE 13, 1907.

1,062,883. Patented May 27, 1913.

3 SEBETS-SHEET 2.

JjHiL J. BURKE.

ELECTRIC RIVETING MACHINE. APPLICATION FILED JUNE 13, 1907.

Patented May 27, 1913.

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Q1?) q N I & 1 F3 Q O [D u; :1 Q Q UNITED STATES-PATENT OFFICE.

JAMES BURKE, OF PENNSYLVANIA, ASSIGNOR TO CHICAGO PNEUMATIC TOOLCOMPANY, A. CORPORATION OF NEW JERSEY.

ELECTRIC RIVETING-MACHINE.

T 0 all whom it may concern:

Be it known that I, JAMES BURKE, a citizen of the United States,residing at Erie, in the county of Erie and State of Pennsylvania, haveinvented certain new and useful Improvements in ElectricRivetingMachines, of which the following is a full, clear, and exactspecification.

This invention relates tocompresslon riveting machines, punches and thelike, and is a machine of this class which is electrically operated.Heretofore, so far as I am aware, machines for doingthis work have beenoperated by steam, air or water pressure.

A further object of my invention is to provide a machine of this classwhich shall be efficient, of simple and compact construction, shallpossess great strength, have the strains equalized and balanced andshall be easily portable.

These and other features of my invention will be understood from thefollowing description and accompanying drawings which disclose one formof my invention in which,

Figure 1 is an elevation of my improved machine, some parts being insection; Fig. 2 is a plan view with certain parts broken away and partlyin section; Fig. 3 is an elevation with parts broken away, and alsopartly in section; Fig. 4 is a rear elevation with part of the gearcasing broken away; Fig. 5 is a section showing details; and 6 is adiagramof electrical connections.

Referring to the drawings, the machine is shown in the general form ofa-yoke, the two branches of which are adapted to straddle the work to beacted upon. The is in general skeleton form as indicate for securinggreat strength and lightness. The

branches 1, 2 of the yoke are provided with guides at their outer ends,for .the rams 3, 4

which carry the, rivet sets or dies 5 of the two oscillating arms 8 onopposite sidesof' the branch 1 of the yokeandto two similar oscillatingarms 9 on opposite sides of the branch 2 of the yoke. These arms arepivoted well in toward the head of the yoke upon cross pins 10, asshown, the fulcrum of the oscillating arms being thus comparatively nearthe head of the yoke. The outer ends of the branches 1, 2therefore-receive Specification of Letters Patent.

oke

only the light strains required for guiding.

the web of the yoke frame and the inner ends of the arms 9, 9 aresimilarly connected. The inner ends of the arms are also each connectedto a nut 11 which travels upon the two screws 12, 13. k The top andbottom of each nut 11 is cylindrical as indicated in Figs. 1 and 5, andupon these cylindrical surfaces bear the inner ends of the links 14which connect the nuts to the ends of the oscillating arms 8, 8, 9, 9.The 'links 14 are shown as made up of an inner end portion 15 whichengages the cylindrical bearing surfaces of the nut 11, and is connectedthereto by clamps 16 which engage an undercut portion of the nut. Theouter portions 17' of the links 14 are pivoted on the inner ends of theoscillating arms, and these outer portions and theinner portions'l5 arecored as indicated, and a sleeve 19 engages and connects each outer andinner portion, the parts being connected by pins 18. The two arms 8, 9on each side are connected to the same nut 11 as shown in Fig. 1, andthe whole thus forms a number of toggle joints when the nuts travelalong the screws 12, 13. The two screws 12, 13 are oppositely threadedfrom the middle outward so that the rotation of the screws in onedirection will cause the nuts 11 to travel toward the outer ends of thescrews'and thus separate the rams, while rotation of the screws in theopposite direction will cause the nuts to travel toward each other, andthus cause the rams to move inthe opposite direction to engage the workacted u on.

An important feature 0 my invention is that instead of mounting anindependent motor upon the yoke for rotating the screws 12, 13, orinstead of separately mounting the motor, I provide that a part of thesteel forming the yoke shall also form the field magnet of the electricmotor and at the same time the yoke will serve to inclose and protectthemotor. 'By reason of this feature, I greatly reduce the weight of thema-- chine and insure convenience in handling and freedom from breakage.I also make the parts easily accessible. In carrying out Patented May27, 1913. Application filed June 13, 1907. Serial No. 378,711. i

- shown in Fig. 3 for clearness.

these features of my invention, I form an opening 21-in the head of theyoke within which extends the field poles 22, 22 and 23, 23 and whichextend from the'main yoke frame. The two poles 22 are made'of sufficientlength to carry the field coils 24, 24:, and the direction of current inthese coils is such as to make the polarity of the poles 22 the same,and the poles 23 therefore become consequent poles of opposite polarity.This. arrangement secures a four pole motor of small width so as to beconveniently located between the screws 12, 13. Within the magneticfield thus formed is located the armature 25 mounted uponshaft 26, whichlatter is journaled at its inner end in the frame of the yoke, and atits outer end in a bearing head 27, which latter is secured to the yokecovering the outer end of the opening 21. .In the bearing head 27 areformed two openings 28. Between the bearing head and the armature .25 islocated the commutator 29 on the armature shaft 26, the armaturewindings and connections not being The commutator brushes 30 are carriedby a brush yoke 31, which in turn is supported by the hearing yoke andfixed in any desired position by bolts extending through slots 32 in thebearing yoke.

On the outer end of the armature shaft is cut a pinion 33 which drivestwo gears 34 on opposite sides thereof. These gears are mounted uponspindles journaled in the bearing yoke and in-the gear casing .35, whichis bolted over the bearing yoke and incloses the various parts. Fixed tothe spindles upon which gears 34 are mounted, are smaller gears 36,which in turn engage and drive pinions 37 on the screw shafts 12, 13.Thus, when the motor is rotating in one direction the screw shafts 12,13 will be rotated in such a direction that the nuts 11 will travel fromthe middle toward the outer ends of theseshafts, and when the electricmotor is rotating in the opposite direction, the nuts 11 will traveltoward each other to the middle of the screw shafts.

The electric motor is preferably of the series wound type, and thereversal of the motor may be obtained by any suitableform of reversingswitch which will reverse the direction of current through either thefield the field windings at 39 and a switch for reversing the directionof current in the" armature is indicated at 40. In series with the motoris connected an adjustable resistance 41 for the purpose of limiting themaximum current which may be passed.

through the motor when operated from a constantpotential circuit. Theadjustment of this resistance will therefore prevent the motor fromreceiving current above a predetermined limit,iand this adjustment willalso determine the maximum torque delivered by the motor. The maximumcompression strain to be exerted. upon the work acted upon by the rams3, 4 is therefore adjusted to any desired amount by adjusting theresistance 41.

In operation, the work being in place and the resistance 41 adjusted togive the desired compression strain, current is introduced intothe motorso .as to give the desired direction of rotation. The motor drives thescrews 12, 13 through the gearing as above explained, and causes thenuts 11, which are assumed to be at, their outer positions, to traveltoward each other. This forces the rams together, and if the workpresents a resistance to the rams as great as the compression strain forwhich the machine has been adjusted, the motor will stop when suchstrain is attained. The resistance 41 will prevent an excessive currentfrom flowing and the motor will thus be protected from excessivecurrent. On the other hand, if the work does not present a'resistance tothe rams as great as the compression strain for which the motor has beenadjusted, the movement will continue until the nuts 11 engage each otherat the middle position when the motor will stop, the resistance 41 thenserving to protect the motor as before.

Reversal of the current through the motor armature will then causeopposite movement of the nuts and open the rams when the next'rivet orother work may be acted upon as already explained. Various means foradjustment of the parts may be used as desired in a manner obvious tothose skilled in the art; for example, the links 14 may be madeadjustable by use of a turn-buckle, or by providing a series ofholesthrough the different parts so that the pins 20 may be passedthrough at any point desired, also sleeves of different lengths may beremovably clamped upon the middle of the screws 12, 13 for limiting theminimum distance between the nuts and so determine the distance betweenthe rams when in their innermost position and similarly sleeves may beclamped over the outer ends of the screw shafts for determining theoutermost positions of the rams. Also it may sometimes be desirable touse reversing gears insteadof reversing the rotation of the motor, andchange gears or interchangeable gears may be used. Also if it is desiredto operate the machine continuously, which may be de sirable for certainclasses of work, any form frame of the motor.

2. In a machine of the class described, a

min, a main frame for supporting the ram" and driving parts, anelectric-driving motor,

the said frame serving-to inclose the motor and form the field framethereof.

3. In a machine of the class describedhaving a yoke frame, 'a ram, andan electric motor within the head'of the yoke for driving the ram, thehead of the yoke forming the field frame for said motor.

4. .A machine of the class described having a yoke, an electricmotor-within the head of said yoke, and means comprising a ram supported.by said yoke for acting upon the i work, said means being driven bysaid motor. 5. In a machine of the class described, a

yoke frame, a ram, an arm pivoted on said frame for operating the ram,an electric motor inclosed by the head of said frame for operating saidarm,,and means between said motor and said arm force exerted.

6. In a machine of the class described, a

yoke frame, a ram, an arm pivoted on said i'frame for operating therain, an electric motor inclosed by the head of said frame for operatingsaid; arm, and means between said motor and said arm for increasing theforce exerted comprising a screw shaft.

7. In a machine of the class described, a

yoke frame, arms mounted on eachbranch of said yoke, rams operated bsaid arms,

an electric motor mounted wit in the headof said yoke, and means drivenby said motor for operating said arms.

for multiplying the 8.. In a machine of the class described, a yokeframe, arms pivoted on the two branches of said frame, rams operated bysaid arms, an electric motor inclosed by the head of said yoke frame,and means comprising a toggle between said motor and said arms formultiplying the force exerted. 9. In a machine of the class described, a

yoke frame, arms pivoted on the branches of said frame, rams operated bysaid arms, an

electric motor inclosed by the head of said yoke frame, and meanscomprising a screw.

shaft between said motor and said arms for multiplying the forceexerted;

10. Ina machine-of the class described, a yoke frame, arms pivoted onboth sides of each branch of said yoke, an electric motor inclosed bythe head of said yoke frame, and means on both sides of said yoke framedriven by said motor for operating said arms.

11. In a machine of the class described, a frame, arms pivoted on saidframe, rams operated by said arms, an electric motor. inclosed by saidframe, and meansfor operating said arms from-said motor comprising aright and left hand screw, traveling nuts,

and connections between said nuts and said arms.

12.v In a machine of the class described, a pair of. rams, arms foroperating said rams, a right and left hand screw shaft, two travelinnuts on said screw shaft, means for driving each of said arms from eachof said nuts, and means for'rotating said screw shaft. t

In testimony whereof I afiix my signature,

in presence of'two witnesses.

JAMES BURKE.

Witnesses:

S! K. SAGER,

Gno. A. IIOFFMAN.

